Investigation of dynamic quality changes and optimization of drying parameters of carrots (Daucus carota var. laguna)

The effect of air temperature and sample thickness on the color changes and total carotenoids content of carrot slices was investigated. Temperature, exposure time, and moisture levels significantly affected the dynamic changes of total carotenoids and color. A slow and linear decrease in total carotenoids was observed at higher moisture content until reaching an inflection point at around 0.45 gw/gdm for all temperatures studied. Thereafter, the retention in total carotenoids decreased rapidly. The highest retention for a final product was 66.2% when drying at 60°C while retention was between 42.2 and 51.1% when drying at 50 and 70°C. These changes occurred alongside a noticeable change in color at moisture contents below the inflection point of 0.45 gw/gdm for all drying temperatures. Design of experiment based optimization of the drying process resulted in an ideal temperature of 59.8°C and 3.5 mm slice thickness with the predicted values for La*b*; ΔE of 62.18 ± 5.12, 22.46 ± 1.98, 40.35 ± 6.64, 6.31 ± 4.74; rehydration ratio of 0.48 ± 0.07; and total carotenoids of 163.83 ± 17.38 μg/g or 67.38%, respectively, all at a 95% prediction interval

Application of the River Habitat Survey method to assessment and classification of hydromorphological state of rivers and streams in south Poland, in accordance with requirements of the water framework directive

In accordance with legacy of the Water Framework Directive membership countries of the EU are obliged to reach at least good ecological state of running waters until 2015. One of the three basic components of assessing ecological state is the determination of hydromorphological conditions occurring in river channels and valleys. In this paper an effort has been taken to check usefulness for such evaluations River Habitat Survey (RHS) – British research method, which is used in Poland for classification of ecological quality of surface waters from the view-point of their actual hydromorphological state. Research was conducted in four upland and lowland rivers and streams of south Poland while each watercourse belonged to another abiotic type. The research released both advantages and disadvantages of the RHS method whereas results of this evaluation pointed at need of developing this method by adding to it, not regarded as yet, the characteristic of hydrological regim

Topological insulator and quantum memory

Measurements done on the quantum systems are too specific. Contrary to their classical counterparts, quantum measurements can be invasive and destroy the state of interest. Besides, quantumness limits the accuracy of measurements done on quantum systems. Uncertainty relations define the universal accuracy limit of the quantum measurements. Relatively recently, it was discovered that quantum correlations and quantum memory might reduce the uncertainty of quantum measurements. In the present work, we study two different types of measurements done on the topological system. Namely, we discuss measurements done on the spin operators and the canonical pair of operators: momentum and coordinate. We quantify the spin operator's measurements through the entropic measures of uncertainty and exploit the concept of quantum memory. While for the momentum and coordinate operators, we exploit the improved uncertainty relations. We discovered that quantum memory reduces the uncertainties of spin measurements. On the hand, we proved that the uncertainties in the measurements of the coordinate and momentum operators depend on the value of the momentum and are substantially enhanced at small distances between itinerant and localized electrons (the large momentum limit). We note that the topological nature of the system leads to the spin-momentum locking. The momentum of the electron depends on the spin and vice versa. Therefore, we suggest the indirect measurement scheme for the momentum and coordinate operators through the spin operator. Due to the factor of quantum memory, such indirect measurements in topological insulators have smaller uncertainties rather than direct measurements

Optimisation of Physical and Chemical Treatments to Control Browning Development and Enzymatic Activity on Fresh-cut Apple Slices

Optimisation of processing time and pre-treatments are crucial factors prior to apple drying to produce a high-quality product. The purpose of the present study was to test the utility of physical (hot-water, HWB and steam blanching, SB) and chemical (1% ascorbic acid, AA; and 1% citric acid, CA) treatments, alone or in combination in reducing surface discolouration as well as oxidative enzyme activity in apple slices (cv. Golden Delicious and Elstar) exposed to air at room temperature for 0, 30 and 60 min. The total colour change (ΔE) for Golden Delicious was equal to 2.38, 2.68, and 4.05 after 0, 30 and 60 min of air exposure, respectively. Dipping in AA solution (1% w/v) was found to be the best treatment to limit surface discolouration of both apple cultivars. The best heat treatments to inhibit polyphenol oxidase/peroxidase enzymes activity were 70 °C HWB for Golden Delicious and 60 °C HWB for Elstar slices, both in combination with a solution of 1% AA and 1% CA. The tested apple cultivars were found to require different treatments at minimum ambient air exposure to obtain the best surface colour condition

QSAR studies on a number of pyrrolidin-2-one antiarrhythmic arylpiperazinyls

The activity of a number of 1-[3-(4-arylpiperazin-1-yl)propyl]pyrrolidin-2-one antiarrhythmic (AA) agents was described using the quantitative structure–activity relationship model by applying it to 33 compounds. The molecular descriptors of the AA activity were obtained by quantum chemical calculations combined with molecular modeling calculations. The resulting model explains up to 91% of the variance and it was successfully validated by four tests (LOO, LMO, external test, and Y-scrambling test). Statistical analysis shows that the AA activity of the studied compounds depends mainly on the PCR and JGI4 descriptors